CVE-2025-55018

Severity: medium (CVSS 5.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-10 · updated 2026-06-17
Weakness: CWE-444

Description

An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header

Affected products

Fortinet FortiOS (FortiGate): from 6.4.3 through 6.4.16; from 7.0.0 before 7.4.10; 7.6.0 — fixed in 7.4.10

How to fix

Upgrade to a fixed version: Fortinet FortiOS (FortiGate) 7.4.10. Check the vendor advisory for mitigations.

References

https://fortiguard.fortinet.com/psirt/FG-IR-25-667
https://cert-portal.siemens.com/productcert/html/ssa-975644.html

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